Improvement in hydro-pneumatic engines



0. FISHER. Hydro-Pneumatic Engine;

No. 215,902, Patented m 27, 1879.

min arses UNITED STATES PATENT nron.

CLARK FISHER, OF TRENTON, NEW JERSEY.

IMPROVEMENT IN HYDRO-PNEUMATIC ENGINES.

Specification forming part of Letters Patent No. 215,902, dated May 27,1879; application filed November 29, 1878.

To all whom it may eoncern:

Be it known that I, CLARK FISHER, of Trenton, in the county of Mercerand State of New Jersey, have invented a new and useful Hydro-PneumaticEngine, of which the following is a specification.

The invention to which this specification relates depends upon thefollowing principle: If the induction orifice of a vertical tube throughwhich a full stream of water or other fluid is passing and beingdischarged into the open air be suddenly closed, the body of fluid belowthe valve will continue, by virtue of its momentum and the force ofgravity, to descend, and thus a vacuum will be formed in the upper endof the tube, and a corresponding atmospheric pressure will be exertedupon the upper side of the valve. As the fall of the fluid progresses,air will rush into the tube from below in quantity sufficient toestablish an equilibrium of pressure on the valve.

It, now, the valve used be of the form of a piston fitting the interiorof the tube, it will be forced down into the tube by the atmosphericpressure above it as the vacuum begins to form; and if the extent of itsdownward motion be properly regulated, (by means, 6. 9., of a springused to suspend it, or by means of a pitman connecting it with acrank-shaft, as hereinafter explained,) the piston will be restored,upon the breaking of the vacuum, to its normal position-i. 6., slightlywithdrawn from the upper end of the tubethis efieet being produced bythe elasticity of the spring, or, when the crank-shaft is used, by themomentum of the revolving parts, the action in either case being aidedsomewhat possibly by the impact of the inrushing air upon the under sideof the valve. This lifting of the valve permits the re-establishment ofthe flow of the water, and this in turn permits the operation to berepeated, the result being a continued reciprocating motion, which can,if desired, be converted into revolving motion by the usual modes.

The accompanying drawings illustrate an engine constructed on thisprinciple, and represent an operative machine, Figure 1 being anelevation of the upper part of the machine, and Fig. 2 a vertical viewof the same.

A is a vessel or tank, which is supplied with water through the apertureB, and from which there extends downward an open tube, 0. E

is a pitman connecting the piston with the crank continues to descend byits acquired momentum and the constantl y-actin g force of gravity. Thistends to create a vacuum within the tube, and the correspondingatmospheric pressure on the upper end of the piston forces it downwarduntil its descent is arrested by the crank reaching the lowest part ofits circle of movement. The momentum acquired by the revolving partsduring the descent of the piston is due to the combined effect of theatmospheric pressure acting on the upper end of the piston, and of theweight of those parts which have been falling from a higher to a lowerlevel. By virtue of this momentum of the revolving parts, the crank iscarried past the deadcenter and up to its first position. This withdrawsthe piston from the tube 0, so that the flower water into the tuberecommeuces. This momentum of the parts carrying the crank past itsupper center, the piston again descends and enters the discharge-tube,

and the operation is repeated so long as the supply of water continues.

By carrying the piston up through a stuffing -box, as shown in Fig. 3,both the length of the piston and the height of the chamber A can bematerially reduced, and at the same time the head of water can beindefinitely increased, the supply 4 pipe B being extended upward, ifdesired, as far as the strength of the parts will permit.

If desired, two or more pistons may be used, connecting with cranks upona common shaft, care being taken to have the cranks so arranged that theseveral pistons will commence their respective ascents at differentpoints of time. In such case, of course, each piston works in anindependent discharge-pipe.

In the construction illustrated in the draw ings, the upper end of thepiston projects What is claimed as new isabove the Water in the feedingvessel. This The combination of the piston and the disis deemedspecially advantageous in a singlecharge tube, when the two are arrangedfor piston engine, since the piston will not be operation substantiallyas described. loaded with Water to impede its rise. *1

It will be observed that this engine is pe- OLARK-FIbHER' culiar in itsconstruction, in that the piston Witnesses acts also as the valve whichgives intermittent SAML. A. DUNCAN, action to the motive power. ROBERTH. DUNCAN.

